The parasitism of immature stages of Ixodes loricatus (Acari: Ixodidae) on wild rodents in Argentina.

Ixodes loricatus has long been considered with strict-total specificity to New World Marsupials. However, frequent findings of its immature stages on rodents suggest that these vertebrates play an important role in the tick's life cycle. Aspects dealing with the ecology of Sigmodontinae rodents infestation by I. loricatus are unknown. To contribute to the knowledge of the ecology of this tick species, environmental factors, as well as host species, sex and age, were evaluated to find associations of immature I. loricatus infestation of the most abundant wild rodent species from riparian locations of Buenos Aires province (Argentina). A total of 290 hosts belonging to the subfamily Sigmodontinae were captured and examined for ticks at six locations. The data analysis showed that there was a preference of I. loricatus towards Akodon azarae, but only for those hosts captured in lands not prone to flooding. The results suggest that the host preference of I. loricatus is mainly related to factors such as habitat type and host density.